Conduit docs: Clarify value type of points in maniphest.edit
Summary: Be less mysterious about the type of value required to edit `points` by explicitly setting `int|float`.
Test Plan:
* Go to http://phorge.localhost/conduit/method/maniphest.edit/#points and look at the Type for the Key `value`, see `int|float` instead of `points`
* See that `EXPLAIN phabricator_maniphest.maniphest_task` lists Type `double` for Field `points`
* Read https://www.php.net/manual/en/language.types.float.php to confirm that float and double are the same in PHP
* Use `maniphest.edit` Conduit API to set Points value of a task, still works
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Differential Revision: https://we.phorge.it/D26338